The NRCS Field Office Guide to Collecting Wildland Seed
Plant Materials Technical Note Number MT-50
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Plant Materials Technical Note
Number MT-50 (PDF; 130 KB)
June 30, 2005.
By Susan R. Winslow, Plant Materials Center Agronomist; Mark Majerus, Plant
Materials Center Manager; Larry Holzworth, Plant Materials Specialist.
The Bridger Plant Materials Center (PMC), in cooperation with the Montana NRCS Field
Offices and associated Conservation Districts, developed a long-range plan
identifying conservation problems that can be solved with plants and/or
propagation techniques. The PMC developed a list of appropriate plant species
required to address those issues. NRCS field personnel are relied upon to
collect wildland seed for initial performance evaluation. The PMC also
encourages species nominations and collections from private landowners and other
state and federal agencies.
What to Collect?
The Plant Materials Specialist sends out an NRCS bulletin every spring listing
high-priority species. The PMC newsletter also publishes the list in the spring
and summer issues. A detailed description of each species and photographs are
available on the Montana NRCS website under Plants and then Collections.
It is important to become familiar with the list prior to field season so that
collection opportunities are maximized. Wildflower populations must be
identified during flowering because it is difficult to locate the plants after
the colorful blossoms have gone to seed. Know what to look for and mark the
site for later visitation to collect seed. A GPS unit comes in very handy to
record site location.
Where to Collect?
Never collect seed from a yard, lawn,
garden, park, or any other obviously cultivated site! Seed should be collected
only in a wildland setting, such as a prairie, valley, hill, mountain foothill,
mountain, etc. It is important to obtain a complete genetic representation, so
sample from many plants, not just a single, or even
several individuals. Plant populations growing in unusually harsh conditions
are very good candidates for collection. Collect as much seed as possible over
an entire area that is environmentally similar in associated plant community
composition, soil type, aspect, and elevation. This means, for example, the
same habitat type, range site, ecological site, etc. Most of the high-priority
species have a very large geographic distribution, so it will be necessary to
conduct several collections across all the counties within a Natural Resource
Area. Always obtain prior permission from the landowner to collect seed.
When to Collect?
The actual time of flowering and fruiting will vary from year to year,
with precipitation and temperature as the driving factors. An early spring and
dry summer may hasten seed set, while lower summer temperatures may delay
flowering and seed ripening. It is necessary to periodically monitor plants for
seed maturity. Generally, seed set occurs 6 to 8 weeks after anthesis
(flowering). Table 1 contains examples of the earliest expected seed collection
dates by Natural Resource Areas. Seed is usually ready to harvest when it feels
firm. Hand cut a cross-section in a few representative seeds to determine stage
of maturity. Figure 1 illustrates the difference between immature seed in a
soft dough stage stage, as compared to mature seed in a hard stage. Seed in the firm
dough stage will continue to mature into viable seed. The trick is to avoid
collecting seed that is green, or immature, but also to harvest prior to shatter
Table 1. Earliest Expected Seed Collection Dates for 10 Genera
of Native Wildflowers for Montana's Natural Resources Areas.
||7/15 to 7/25
||7/17 to 8/1
||8/8 to 8/15
||9/1 to 9/12
||8/10 to 8/15
||8/15 to 8/20
||7/25 to 8/1
||8/29 to 9/6
||9/24 to 10/8
||9/22 to 10/1
||9/14 to 9/22
||8/5 to 8/12
||8/12 to 8/20
||9/1 to 9/5
||8/23 to 8/28
||8/20 to 8/25
||7/28 to 8/5
||7/25 to 7/29
||8/11 to 8/20
||8/25 to 8/29
||8/12 to 8/17
||8/5 to 8/10
||8/11 to 8/16
||8/14 to 8/18
||8/6 to 8/12
||8/7 to 8/14
||8/5 to 8/10
||8/5 to 8/11
||7/21 to 7/31
||7/31 to 8/4
||8/24 to 8/28
||7/15 to 7/22
||7/6 to 7/10
||6/20 to 7/4
||7/27 to 8/4
||6/28 to 7/15
||7/18 to 7/27
||7/20 to 7/26
||8/15 to 8/20
2 Gaillardia aristata
3 Liatris punctata
5 Phacelia hastata
6 Psoralidium tenuiflorum
7 Ratibida columnifera
8 Sphaeralcea coccinea
9 Thermopsis rhombifolia
10 Vicia americana
NA-No knowledge of specimen record housed in Montana State University Herbarium.
Figure 1. Immature, soft dough stage on the left,
and mature, hard stage on the right.
How to Collect
A physical examination of the seed is crucial! Take time to visually inspect
for signs of immaturity.
There should not be any
remaining sign of flowering parts, such as anthers, stamens, or petals on
the plant. Try to collect seed during dry weather because excess moisture
is fatal to seed viability.
- Remove a small portion
of the inflorescence and rub vigorously in the palm of the hand to loosen
the seed from the stalks. It may be necessary to use a hand lens or other
eye aid to get a close enough look to identify the seed.
Carefully sort through
the chaff for seeds and check readiness by clipping with a fingernail
clipper, cutting with a knife, or biting between teeth. The latter
technique should not be employed if the plant is known to be poisonous!
The seed is ready to
harvest when no doughiness is evident and the endosperm is firm. No
moisture should be present when the seed is cut or rubbed in the palm of the
hand. Mature seed ranges in color from tan to dark brown, and rarely is
green. It will be necessary to check several plants in the immediate area,
as ripening will vary among individuals. Waiting a few days may result in a
more fully mature seed crop.
Native legumes are very
often attacked by seed predators. Carefully cut open a few seed and inspect
for the presence of live larvae. Make sure there is not just an empty shell
left behind after the insect consumed and vacated the seed. Another clue is
the presence of a minute entrance hole where the insect accessed and vacated
through the seed coat.
Use a sharp utensil,
such as scissors, knife, hand-scythe, or clippers to remove the
inflorescence and a small amount of stalk. In many instances where the size
of the area and number of plants is moderate, it is just as easy to
hand-strip. It is best to harvest only the inflorescence or seed structure,
as unnecessary vegetation such as leaves and stems, add undesirable moisture
and bulk. In the case of indeterminate flowering (different stages
occurring on a plant at the same time), a greater amount of material should
be harvested to allow more seed to mature.
Gloves may be needed
for handling the sharp or stickery capsules and pods of some species.
Collect as much seed as
possible, while only taking approximately 20% of the total seed crop in a
At this time of the
year, many of the plants will be very dry and brown in appearance. If
possible, choose only to harvest from healthy, robust plants.
material in paper sacks with adequate room for air circulation to promote
Do not store seed for
any length of time in plastic sacks! Plastic holds moisture and increases
temperature and humidity, which very quickly promotes mold and damages the
Label each sack with
the species, collector’s name, and the date.
Complete in full, the NRCS-ECS-0580: Plant Collection Information
Form available through
USDA Service Center eForms (USDA employee
- Record a
description of all physical characteristics, such as elevation, aspect,
slope, soil texture, annual precipitation, MLRA, associated species, and
ecological condition. Accurately record site location with the use of both
a GPS unit and a topographical map to document the township, range, and
section, and the proximity of landmarks, such as geographic formations,
roads, rivers, bridges, structures, land ownership, etc. This is important
because it may be necessary to re-visit the site sometime in the future.
- After transporting,
leave the sack open and periodically stir up the contents to promote
drying. It is best if material can be spread out on a flat surface to dry
at room temperature. When curing is complete, temporarily store the bag in
a place that is cool and dry until it can be sent to the Bridger PMC.
Where to Send?
Mail or deliver seed collections to the following address:
USDA NRCS Plant Materials Center
98 South River Road
Bridger, Montana 59014
The PMC processes the material to clean seed, assigns an accession number to
each viable collection, and periodically installs Initial Evaluation Plantings
to test the performance of individual collections against one another. Assigned
accession numbers are sent to the original seed collector(s) so they also can
track the reported performance of the material throughout the testing and
selection process. Superior performing material will proceed to Comparative
Evaluation Plantings, Seed Increase, Field Evaluation Plantings, and eventual
selection and release for distribution to the commercial seed industry.
How Does this Help?
The NRCS Field Offices play a
vital role in the continued testing and selection of native species that help to
conserve and protect the natural environment. The
PMC’s plant release tool-box of 26 grass, forb,
legume, tree, and shrub species, will, with the assistance of the Field Offices,
continue to grow and be beneficial in
biomass production, carbon sequestration, erosion reduction, wetland
restoration, water quality improvement, streambank and riparian area protection,
and other special conservation treatment needs.
Need More Details?
Additional information can be found
in the following references:
- Plant Materials Collection Guide, Technical Note Plant
Materials Number 1, USDA NRCS Boise, Idaho,
Technical Note Number 35, USDA NRCS Brooksville, Florida,
Processing, and Germinating Seeds of Wildland Plants, J.A. Young and C.G.
Young, Timber Press, October 1986.
If you have any questions, please contact
one of the following:
Susan Winslow, Agronomist
Phone: (406) 662-3579
Plant Materials Specialist
Phone: (406) 587-6995
State Resource Conservationist
Phone: (406) 587-6998
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